Smart meters, and other smart grid devices, such as streetlights, load control devices, sensors, etc., that are used by utilities and other similar types of entities are often loaded with specific cryptographic credentials of the owner to ensure that the utility or other entity has access to operations of the smart device, while preventing access for others. In many instances, a set of cryptographic credentials associated with a utility may be used across a plurality of their smart meters, such that a valid set of credentials can be used by an employee or authorized user to access each of the smart meters, without the need to possess a large number of credentials or remember what credentials are for which device.
When a smart grid device has a problem and must be repaired, the utility can return the smart grid device to the device vendor, a repair vendor, or other suitable entity in order to assess the problems and repair the smart grid device. However, if a smart grid device has cryptographic credentials on it that tie it to a specific owner, vendors are often unable to access vital operations of the smart grid device unless in possession of the appropriate owner credentials. In many instances, a utility may be wary of providing proper cryptographic credentials to the vendor, as it can provide the vendor with access to all of the utility's smart devices and not just the problematic device.
One method that is used to remove credentials from a smart grid device includes tampering with a smart grid device that is configured to remove all credentials from the device when tampering is identified as part of previously configured anti-tampering mechanism. However, in some instances the removal of all of the credentials from a device may not be desirable, as the device may therefore require additional steps in refurbishment in order to return the device to working order. For example, a smart meter that has networking capabilities may require security credentials for the network in addition to security credentials used by a utility for utility operations. If the smart meter was tampered with as part of a repair or servicing process, the network security credentials would need to be loaded back onto the smart meter prior to reuse of the meter, which may cost significant time and resources for both the servicing vendor and the entity responsible for the network security credentials.
Thus, there is a need for a technical system where a specific set of cryptographic credentials can be removed from a smart grid device by a vendor without use of the credentials themselves.